SNOWMASS, COLO. – Transcatheter aortic valve replacement in nonsurgical candidates with severe symptomatic aortic stenosis carries a hefty price tag of $116,500 per quality-adjusted life-year gained over medical management.
That’s the bottom line in a cost-effectiveness study led by cardiologist Dr. Mark A. Hlatky. The investigators applied data on the costs and benefits of transfemoral transcatheter aortic valve replacement (TAVR) as documented in the landmark PARTNER (Placement of Aortic Transcatheter Valves) trial in their Markov model involving a hypothetical patient cohort. The estimated incremental cost-effectiveness of $116,500 per quality-adjusted life-year gained is well in excess of the $50,000 figure widely accepted by health policy makers as defining a cutoff for cost-effective therapy.
Dr. Mark A. Hlatky
In this cost-effectiveness analysis (Circ. Cardiovasc. Qual. Outcomes 2013;6:419-28), TAVR boosted life expectancy by roughly 11 months, from 2.08 years with medical therapy to 2.93 years. Quality-adjusted life expectancy rose from 1.19 to 1.93 years. TAVR also resulted in 1.4 fewer hospitalizations than with medical management. However, undergoing TAVR rather than medical management raised the lifetime stroke risk from 1% to 11% and increased lifetime health care costs from $83,600 to $169,100, reported the group led by Dr. Hlatky, professor of health research and policy and also professor of medicine at Stanford (Calif.) University.
"This is a fascinating study," Dr. Karen P. Alexander said at the Annual Cardiovascular Conference at Snowmass. "I think the lesson here is that futility from a cost perspective is also something that should be in the discussion" regarding TAVR vs. medical therapy in patients with inoperable aortic stenosis.
She highlighted the Hlatky study in discussing the key role frailty assessment plays in considering TAVR. The study showed that the cost-effectiveness of TAVR is greater in patients with a lower burden of noncardiac disease, which is another way saying "those who are less frail."
This conclusion underscores a statement in the 2012 American College of Cardiology/American Association for Thoracic Surgery/Society for Cardiovascular Angiography and Interventions/Society of Thoracic Surgeons expert consensus document on TAVR paraphrased by Dr. Alexander: Frailty will assume central importance in patient selection for TAVR by virtue of the extensive comorbidities in this population. Existing models do not have predictive variables of interest in high-risk patients. (J. Am. Coll. Cardiol. 2012;59:1200-54).
Dr. Alexander of Duke University in Durham, N.C., said frailty is important when considering TAVR because it has been shown to be associated with increased rates of post-TAVR 30-day morbidity and mortality, prolonged hospital length of stay, and 1-year mortality.
She defined frailty as a multisystem impairment resulting in reduced physiologic reserve and increased vulnerability to stress. Frailty is a physiologic phenotype associated with slow gait, weakness, weight loss, exhaustion, and a low daily activity level.
While the degree of a patient’s frailty is an important consideration in deciding on TAVR vs. medical management, frailty per se is no contraindication to the procedure. Indeed, the prevalence of frailty as defined simply by a baseline 5-meter walk time in excess of 6 seconds was 72% among the 7,710 TAVR patients, mean age 84 years, included in the recent first report of the comprehensive national STS/ACC Transcatheter Valve Therapy Registry (JAMA 2013;310:2069-77). That’s nearly twice the 38% prevalence among community-dwelling 85-year-olds, Dr. Alexander noted, citing data from the Canadian Study of Health and Aging (CMAJ 2011;183:e487-94).
More than 20 different frailty risk scores are now in circulation. Dr. Alexander is particularly enthusiastic about the frailty risk tool developed as part of the ACC’s new Championing Care for the Patient With Aortic Stenosis Initiative. It efficiently assesses five domains of frailty – slowness, weakness, malnutrition, inactivity with loss of independence, and malnutrition – and generates a clinically useful qualitative frailty rating. A patient with a high frailty score may not have sufficient life expectancy to obtain the benefits of TAVR.
With regard to treatment futility, Dr. Alexander observed that it can be defined as either lack of medical efficacy as judged by physicians or as lack of meaningful survival as judged by a patient’s personal values. Yet one in four Americans aged 75 years or older has given little or no thought to their own wishes for end-of-life medical therapy, according to a recent Pew Research Center survey.
The telephone survey, conducted last spring, included a representative sample of 1,994 U.S. adults. While 47% of respondents aged 75 years or older indicated they had given their own wishes for end-of-life medical care a great deal of thought, 25% said they had given the matter "not much or none." Reflection on those personal wishes needs to be part of the physician/patient discussion about TAVR, according to Dr. Alexander.